Turns-indicating knob



1964 M. E. BOURNS ETAL 3,151,598

TURNS-INDICATING KNOB Filed Jan. 21, 1963 INVENTORS 'MARLAN 1 Baum/WYL/E A. 570a:

United States Patent 3,151,598 TURNS-INDICATING KNOB Marlan E. Bourns,Riverside, and Wylie A. Stout, Arlington, Calif., assignors to Bourns,Inc. Filed Jan. 21, 1963, Ser. No. 252,904 13 Claims. (Cl. 116--115) Theinvention herein disclosed pertains to indicator devices that are usefulfor indicating the number of turns and fraction of a turn through whichan adjusting shaft is rotated from a prescribed rotational startingposition or zero. Actuating or adjusting shafts of the type here ofconcern are found, for example, in multiturn rotary potentiometers, inwhich instruments rotation of the shaft serves to variably position amovable electrical contact along an exposed face of a helical resistanceelement that is disposed in coaxial relationship with the shaft. Forillustrative purposes only, the present invention will be described inconnection with such an instrument, it being understood that theexemplary illustrated physical embodiment of the invention is capable ofuse and operation with other devices or instruments wherein the rotationof the actuating shaft through a number of revolutions, twentyforexample, drives the instrument through its effective operating range.The primary purpose of turns-indicators is to facilitate rapid return orsetting of the actuating shaft and the operated part to previouslyoccupied positions. A subsidiary purpose is to provide a visibleindication of the position of the operated part relative to the endpositions of its movement range.

In the prior art many differing constructions of muliple' turns countersor, turns-indicators have been marketed. Many utilize gearing or likeexpensive parts in providing indications of complete turns andfractional-turn rotation. Many of shaft-adjusted instruments are mountedon or at the rear ofa panel or the like through which the actuatingshaft extends, and accordingly it is undesirable, in general, for theindicator to occupy a large space. Many of prior art turn-indicators aresuch that reading indications of two widely spaced-apart members, onefor full turns and the other for fractions of one turn, is required,making reading unnecessarily diflicult and more prone to error. Quiteoften the turns-indicating means are combined with knob-means or thelike that are utilized to facilitate rotation of the adjusting shaft.The indicator means are in instances added onto the exterior of theknob, or utilize a set of indicia that are inscribed upon or otherwisecarried by the panel on which the instrument is mounted.

The aforementioned undesirable features of prior art shaft-positionindicators are avoided by the present invention. According to theinvention, the operating structures necessary to give movement toindicating devices take the place of the usual operating knob. Theindicating devices are very simple, comprising a stationary dial orplate bear-ing indicia, a handlike mark applied as by painting on atransparent crystal or cover, and a rotatable hand. The indicatingdevices are arranged at the outwardly-facing end of the knob-likeoperating structure that serves as the adjustment knob, and present aneasily-read indication similar to that presented by a time clock orwatch. Thus the panel space required is exactly the same as thatrequired by the normally-used solid knob, and indicia or other markingon the panel is not necessary. The indicating structure, being at theouter end-face of the knob-like operating means, is clearlyvisibleduring adjustment of the shaft. The device according to theinvention has the shape and general configuration of a shaft-operatingknob, is mounted" upon and secured to a shaft by the same means and inthe same manner as a conventional knob, and hence supplants and replacesthe usual knob. Being devoid of gears and constructed of very few andsimply and easily assembled parts, the device is inexpensive, yet veryeffective.

In general the preferred form of the invention comprises a supportarranged to be secured to the forwardly extending adjustment shaft, forrotation of the shaft, by means of a set screw. The support has affixedthereto a lens or crystal and a generally cylindrical structure orbarrel that is adapted to be manually rotated. .Thus manual rotation ofthe barrel effects rotation of the shaft. The lens or crystal,hereinafter called a window for convenience, bears a pointer or handthat may be painted on the inner surface of the lens, and it furtherserves to hold against a panel the rear end of a stationary cylindricalguide and retainer device. The retainer part includes an annular dial,and serves to retain in place a floating rotary device or wheel thatcarries a second hand or pointer and is intermittently rotated bycam-and-transmitter means incident to rotation of the outer barrel. Thestationary cylindrical guide bears the cam means for inducingintermittent rotation of the wheel, and preferably also serves tostabilize the rotatable barrel. The wheel is rotatable on the support,and is retained in any of predetermined angular positions indicatingfull turns (or full turns and half turns) by a simple spring detent thatyields each time the cam means induces a step of rotation. Thus as thebarrel is rotated the first pointer is concurrently rotated over theface of the dial to provide indications of fractional portions of a fullturn, and the second finger is intermittently stepped to indicate fullturns of the shaft.

The preceding brief general description of a physical embodiment of theinvention indicates that it is a principal object of the invention toprovide improvements in turns-indicators for instruments having anadjusting shaft that is rotated to effect adjustment of the instrument.

Another object of the invention is to provide a simple turns indicatorfor indicating the extent of rotation of an adjusting shaft from aninitial position.

An additional object of the invention is to provide a device that may beused in place of a shaft-operating knob for rotatively adjusting theshaft and which device Will provide easily read indications of theextent of rotation of the shaft from an initial position.

Other objects of the invention will hereinafter be set out in the claimshereto appended or made evident in the following description of apreferred exemplary embodiment of the invention as depicted in theaccompanying drawings. In the drawings:

FIGURE 1 is a view of a panel-mounted ten-tum instrument with apreferred exemplary form of the invention mounted thereon;

FIGURE 2 is an end or face view of the turns-counting or indicatingdevice depicted in operating position on a panel-mounted instrument inFIG. 1;

FIGURE 3 is a sectional view of the preferred exemplary embodiment ofthe invention, enlarged for clarity of detail, taken as indicated byline 33 in FIG. 2;

FIGURES 4, 5 and 7 are fragmentary sectionial views of the structuredepicted in part in FIG. '3, taken as indicated by lines 4-4, .55, and7-7, respectively in FIG. 3; and

FIGURE 6 is a face view similar to FIGURE 2 of the dial indicatorfollowing rotation of the instrument shaft through one and three-tenthsturns.

Referring first to FIG. 1, there is denoted generally by numeral 10 aknob-like structure or device according to the invention as constructedto accommodate an instrument shaft rotation of ten turns (3600") orless. The device is illustrated as being mounted on the adjusting shaftof an instrument 12 in the form of a ten-turn rotary potentiometer thatis in turn affixed tothe rear face of a panel 14. Next referring to FIG.3, it is noted that the instrument 12 comprises a threaded bushing 12bthat extends through an aperture 14a formed in the panel 14, the bushingbearing a nut 1211 by means of which the bushing and instrument properare held rigidly to the panel. Additionally the instrument comprises anadjusting shaft 12s rotatably mounted in the bushing 12b and extendingoutwardly and forwardly therefrom. The free end of the shaft comprisesthe portion upon which a conventional adjusting knob is usually secured.

The exemplary embodiment of the invention utilizes supporting meanscomprising a generally tubular support (FIG. 3) that is bored to receiveand be secured to an end portion of the instrument shaft 12s. Anysuitable means may be used to affix the support to the shaft, but asillustrated the support is secured to the shaft by set screw meanscomprising a set screw 29s. The reduced forward end 20 of support 24) isaxially bored and tapped to receive a screw 22. The screw 22 serves tofirmly secure to the support for unitary rotation in unison therewith ahollow shell means which with the support serves as the essentialelements of a manually-rotatable knoblike means for imparting rotationto the instrument shaft. The shell means in the illustrated embodimentcomprises at the outer end thereof a transparent lens or window 24 thebeveled outer periphery of which is tightly fitted into a counterboredouter end of a hollow cylinder or barrel 26 forming a part of the shellmeans. The window or lens 24 and the cylinder may be firmly securedtogether, as by adhesive or the like, so that torque applied to eitheris applied through the support to the instrument shaft. Lens 24 hasapplied thereto on its inner face an indicator in the form of an outerpointer 24p, for a purpose presently more fully explained. The pointer24p may be painted on lens 24, as previously indicated. Barrel 26 isrotatably disposed around stationary means which in the illustrated formcomprises a generally cylindrical sleeve 28, the rear end of which abutsagainst the front face of p panel 14. The sleeve is retained in positionby reason of an annular step 28s formed on the exterior of the sleeve,the step being engaged by the rear end face of the barrel when thedevice is pressed onto shaft 12s and the set screw means are tightened.The sleeve 28, or other part of the stationary means, also comprises camelements presently to be described.

Secured to or forming an integral part of the forward end of sleeve 23is an annular ring 28r. Secured to the outer end face of ring 28r (or,alternatively, integral with the ring) is an indicia-bearing indicatormeans in the form of a disk 30. The disk is provided with marksindicating subdivisions of 360, and numerical indicia which preferablycommence with zero and are equal in number to the number of turns shaft12s must be rotated to operate the instrument through its completerange. Thus the disk and indicia serve as a dial. In the exemplarydevice used with the exemplary ten-turn potentiometer the numericalindicia are as depicted in FIGS. 2 and 6; however other sets of indiciamay be used. The disk or dial is annular in form, to provide an openingthrough which the front end of support 20 extends.

Rotatably mounted on support 20 and bearing on rear and forward steps20a and 20b, respectively, of the sup port, is an intermittentlyrotatable means comprising an externally toothed rotatable manner 32hereinafter called a wheel. The wheel, as is indicated in FIGS. 4 and 5,is formed to have a set of axially extending projections or teeth 32tbetween next-adjacent ones of which teeth are axially-extending groovesthat preferably are of substantially circular-arc cross-section. Theteeth and intervening grooves are engaged by a driving member ortransmitter and by detent means presently to be described, whereby thewheel is alternatively driven and retained stationary, for purposes orreasons also presently explained; Secured to the reduced-diameterfront-end or hub portion 32h (FlGl 3) of the wheel 32, is an indicatordevice in the form of an inner pointer 32p which preferably is formed asan annular ring closely fitting on hub 32h and secured thereto andhaving an integral projection forming a pointer or hand that cooperateswith the numerical indicia on disk 30 to provide indications of fullturns through which shaft 12s has been rotated from an initial or zeroposition. The arrangement of inner pointer 32p relative to hub 32h, dialdisk 30 and the indicia thereon is illustrated in FIGS. 2, 3 and 6.

Secured in a bore formed through a rim portion of support 20 (FIG. 3)generally opposite set screw 20s, is a transmitter means comprising aresilient reed 34. A notch or slot Ztin (see also FIG. 7) is provided inthe rim of the support, in which notch a free portion of the reed canpartake of radial bending movements under the influence of actionspresently to be described. Mounted on the free end portion of the reed34 and preferably rotatable thereon is a dog or transmitter 36. The reedis normally straight and thus transmitter 36 normally is in an idle orinactive position in which it travels along a first circular path and incontact with or close to one or another of a set of surfaces 28v, 28w(FIG. 4) intervening between specially spaced and formed projections orcams 280 formed or otherwise provided along a portion of the interiorperiphery of stationary sleeve 28 and in said first circular path. Thusit is evident'that upon rotation of shaft 12s and support 20, the reed34 and transmitter 36 are carried around within sleeve 28, andtransmitter 36 engages or collides with one of the cams and is forcedradially inwardly away from the first (outer) circular path into asecond (inner) circular path, and, after riding over a cam, is returnedoutwardly to the first path by the energy stored in the resilient reedduring the inward motion. Obviously the same action occurs irrespectiveof the direction of rotation of shaft 12s. As is made evident byexamination of FIGS. 3 and 4, as the transmitter 36 is forced inwardlyas it engages one of the cams during rotation around the axis of theshaft, it is moved into one of the grooves 32g intervening betweennext-adjacent ones of projections or teeth 32t of wheel 32. Since thereed and transmitter are forced to rotate about the axis of the shaft inunison with the barrel and support 20, engagement of the transmitterwith a tooth of wheel 32 causes rotation of the latter and displacementof inner pointer 32p.

Rotation of wheel 32 by the transmitter is thus restricted to discretesteps of movement; preferably and as herein disclosed, to twice as manysteps as the number of full turns or revolutions of shaft 12s necessaryto accomplish full-range variation of instrument 12. The angulardimensions and dispositions of the cams and teeth are thus governed bythe number of full revolutions of shaft 129 required to adjust theinstruments through its entire adjustment range. Also, the wheel ispreferably locked or yieldingly restained against undesired rotationduring the indeterminate variable operating interval or I period betweenstepwise rotational movements. To those ends, a shaped resilient springdetent 38 (FIGS. 3 and 5) is provided, which detent has the ends of itshorns anchored in respective radial slots that are provided for thepurpose in ring ZSr. The intermediate or middle part of the detent 38 isformed as indicated in FIG. 5 for close seating in any of grooves 32gand for cooperation with any pair of teeth 321 to forcibly butyieldingly restrain wheel 32 from unintended rotation. The freeunanchored body portion of the detent is resilient and accordinglyyields and permits the middle part to ride out of a groove and over atooth into a next-adjacent groove when transrnitter 36 forcibly rotatesthe wheel. Thus it is evident that during each revolution of shaft 12sas barrel 26 is rotated, the'transmitter will encounter each of the setof cams (of which-there are two in the illustrated embodiment) and willbe forced inwardly and thereby rotate the wheel and inner pointer 32pthrough a definite fractional part of a turn in the same rotationaldirection as that of vthe barrel. As is also evident, the rotation ofthe barrel 2-6 andlens or window 24 will move 'outer pointer 24p aroundthe series of indicia through precisely the same angular extent ofrotation as that of adjustment shaft 12s. As a consequence, outerpointer 24p will, during each revolution of the shaft, provide areadily-perceptible and very accurate indication of the fraction of .aturn the shaft has been rotated from the initial or zero position. Also,inner pointer 32p will, during a series of successive revolutions of theshaft from zero position, furnish indications of the number of full(360) turns through which the shaft has rotated. Thus, with theinstrument set at the initial or zero end of its range of adjustment,with the pointers 32p and 24p set at zero positions, and the set screwmeans then tightened to affix the illustrated exemplary (IO-turn) deviceto shaft 12s, rotation of the barrel in the forward or clockwise senseas viewed in FIG. 2 will during the first one-third of a revolution moveonly outer pointer 24p of the indicator pointers. Then, during thesecond one-third of the first revolution, the transmitter will engageone of cams 28c and enter a groove of wheel 32 and rotatepointer to aposition approximately midway between numerals and 1 on disk 30. Then asforward rotation continues and outer pointer 24p approaches and passesnumeral 0, the transmitter will engage another of cams 28c and causerotation of wheel 32 through another step and to a' position at whichinner pointer 32p points to numeral 1 on the dial or disk 30. Theactions will be generally repeated during each succeeding' revolution ofthe barrel and shaft, inner pointer 32p stepping twice during each'revolution. During return movement of the instrument by subsequentbackward rotation of the barrel and shaft,the stepping of wheel 32 andits inner pointer 32;; will be in the return direction. The illustratedembodiment of the device'accordi'ng to the invention is arranged for usewith an instrument having an adjustment shaft that is rotated clockwisefrom the zero or'initialposition. Obvious rearrangement of the indiciato read counterclockwise is contemplated in a similar device for usewith an instrument operable in the counterclockwise direction from theinitial position.

For decoration and reinforcement of barrel 26, a ring 40 (FIGS. 1 and 3)may be affixed to the end'of the barrel. The barrel may be provided withlongitudinally-extending fiuting 26] (FIGS. 1, 4 and 5) whereby tofacilitate manual rotation of the barrel, and, optionally for anotherpurpose. Thus, in these instruments in which it is desired tosecure orlockthe instrument in a particular position of adjustment, a closelyfitting internally fluted cy lindrical band or slide 42 may be used inconjunction with complementary flutin'g formed on the rear step 28! ofsleeve 28 (FIG. 3), the fiuting being complementary to that on barrel26. Thus with slide 42 inthe dashline position indicated in FIG/3, inwhich the slide is wholly on barrel 26, the barrel may be rotated to anydesired rotational position withoutrestraint from slide 42. Thereafter,theslicle 42 may be pushed back to the full line position indicated inFIG. 3; in which position it is engaged'with'both the'barrel' and sleeve28, and thus serves to lock the barrel to the sleeve. Sleeve 28 isprevented from rotating by a projection 44p' (FIG. 3) provided on theinstrument lock-washer 44, which projection is arranged to be disposedin a complementaryslot 28m provided in the lower rear edge of sleeve 28..Thus the slide may be used to lock the barrel to-stationary structureand prevent accidental rotation of the barrel and the shaft of theinstrument. To then permit change of adjustment or setting of theinstrument the slide 42 is drawn forwardly until it is free of sleeve 28as indicated in the dash-line position inFIG. 3.

The preceding description of a preferred exemplary embodiment oftheinvention illustrates the attainment of the aforementioned objects.It is evident that in the light,of the disclosure, modifications, suchas changes of form, within the, true spirit and scope ofthe inventionwill occur to those skilled in the art. For example, it is obvious thatparts'28, 28r, and 30'may be formed as a single casting as byinjection-molding; and the same is true of parts 26 and 40. Accordinglyit is not desired to limit the invention to the exact structure of thepreferred exemplary embodiment illustrated and described, but we claim:

1. For an instrument having an adjusting shaft rotatable through aplurality of revolutions in effecting adjustment of the instrumentthroughout its adjustment range, a turnsindicating knob structurecomprising:

first means, including a support device having a bore along an axis andadapted for mounting upon the instrument shaft coaxially with the shaft,said device including means to secure the support device to the shaftfor positive rotation in unison with the shaft about the axis thereof;second means, comprising rotary means secured to said support device andproviding a knob-like exterior adapted to be manually rotated forrotation of said support device and the instrument shaft, said rotarymeans comprising a transparent window disposed transversely of said axisand providing an outer end face for the rotarymeans, said rotary meansbearing an outer indicator movable in unison therewithand visiblethrough said transparent window; third means, including stationary meansencircling at least a portion of said support means and having cam meansand an indicia-bearing dial having a face area visible through saidwindow; fourth means, comprising a toothed device rotatably mounted onsaid first means and an inner indicator pointer thereon arrangedclosely-adjacent to and in front of said dial, said toothed devicehaving a peripherally disposed set of teeth; and movable transmittermeans carried by said support device for rotation therewith and disposedin the path of said cam means and movable thereby into engagement with atooth of said toothed device whereby said toothed device isintermittently rotated incident to rotation of said support device tomove said inner indicator pointer relative to said indicia,

whereby said inner indicator pointer and said outer pointer moverelative to said indicia to indicate full turns and fractions of a turn,respectively, of said support means.

2. A turns-indicating knob structure according to claim 1, saidstationary means comprising generally cylindrical sleeve means coaxialwith said support device and having an exterior bearing surface coactingwith said rotary means.

3. A turns-indicating knob structure according to claim 1, saidstationary means comprising an externally-serrated. generallycylindrical surface, and said rotary means comprising a complementarysimilarly externally-serrated generally cylindrical surface, and lockmeans, comprising an internally-serrated band coaxial with said supportmeans and movable longitudinally for concurrent interengagement of theinternally-serrated surface thereof with the externally-serratedsurfaces of said stationary means and said rotary means to locktherotary means to the stationary means to prevent inadvertent rotation ofthe rotary means, and said band being longitudinally movable to aposition out of engagement with one of said externallyserrated surfaces.

4. A turns-indicating knob structure according to claim 1, said dialbearing numerical indicia in serial order commencing with zero and equalin number to the number of revolutions required of said shaft foradjustment of the instrument throughout its range, and said cam meanscomprising a plurality of cams uniformly spaced about the internalperiphery of said stationary means, whereby said inner pointer isadvanced in stepwise movement betwen next-adjacent ones of saidnumerical indicia.

5. A turns-indicating knobstructure according to claim 1, said cam meanscomprising two uniformly-spaced cams and said toothed device ComprisingN uniformly-spaced teeth where N is an even whole number, and said camseach being of configuration to move said transmitter to engagement witha tooth of said toothed device through a fraction of one revolution ofsaid rotary means, said fraction being expressed as l/N, and theinstrument shaft being rotatable through N/Z revolutions to operate theinstrument through the complete adjustment range thereof.

6. A turns-indicating knob structure according to claim 1, includingresilent means secured to said stationary means and pressing saidtoothed device whereby to yieldingly retain the latter in any positionto which the toothed device is rotated by said transmitter.

7. For an instrument having an adjusting shaft rotatable through aplurality of revolutions in effecting adjustment of the instrumentthroughout its adjustment range, a turns-indicating knob structurecomprising:

first means, including a rotary structure having a bore for reception ofan end portion of the adjusting shaft of the instrument, said rotarystructure including means to secure the rotary structure to said shaftfor rotation in unison therewith, said rotary structure comprising agenerally cylindrical shell adapted for manual rotation and having anend member providing at least a circular transparent window and an outerpointer rotatable therewith; second means, comprising stationary meansmechanically connected to said first means and including a dial havingat least annular face visible through said window, said dial bearing acircularly arranged set of indicia visible through said window, and saidstationary means comprising cam means;

third means, comprising rotatable means mechanically connected to saidfirst means and having an inner pointer means rotatable between saidwindow and said indicia;

fourth means, including transmitter means connected to and rotatable inunison with said rotary structure into intermittent engagement with saidcam means for actuation by the latter into driving engagement with saidrotatable means whereby to intermittently connected to and movable inunison with said rotary structure to intermittently move said pointermeans past some at least of said indicia;

and second pointer means visible through said window,

connected to the movable in'unison with said rotary structure past saidindicia incident to rotation of the rotary structure,

whereby said second pointer means provides a visible indication offractional portions of each complete revolution of said rotary structureand said first pointer means provides a visible indication of the numberof full revolutions of displacement of said rotary structure, from areference position.

8. A turns-indicating knob-like structure for use in rotating theadjusting shaft of an instrument requiring rotation of the shaft througha plurality of revolutions for adjustment throughout the range of theinstrument, said structure comprising:

support means arranged to be secured to the instrument shaft forrotative movements in unison with that shaft and including shell-likemeans simulating the surface of a knob and having a window at an endthereof;

resilient transmitter means secured to said support means for rotationtherewith along a generally circular first path and movable relativethereto from said first path into a circular path;

stationary means, including means mechanically connected to said supportmeans and presenting cam means disposed in at least part of the saidfirst path whereby the transmitter is moved into contact therewith andis forced tomove from the said first path into and along the said secondpath and return,

and said stationary means comprising an indiciabearing dial visiblethrough said Window; and

rotatable means including a structure having a pointer rotatable closelyadjacent the indicia on said dial and having a series of projectionseach movable along said second path into position to be engaged by saidtransmitter means incident to movement of the transmitter from saidfirst path into and along said second path,

whereby incident to rotation of said support means said rotatable meansis intermittently rotated to move said pointer in stepwise movementspast in dicia on said dial to provide a visible indication of the numberof revolutions through which said support means and the instrument shafthave been rotated from a zero position.

9. A turns-indicating knob-like structure according to claim 8,including a second indicator in the form of an outer second pointer,secured to said support means to rotate in unison therewith and having aportion thereof rotatable in front of and past said indicia behind saidwindow, whereby said second indicator provides an indication offractional parts of a revolution through which said support means hasbeen rotated from each of initial positions.

10. A turns-indicating knob-like structure according to claim 8, saidtransmitter means comprising a resilient reed secured to said supportmeans and having an end portion free to bend radially and a ballrotatable on the free end and disposed for engagement by said cam meansand movable thereby into engagement with successive ones of saidprojections.

11. A turns-indicating knob-like structure according to claim 8, saidstationary means comprising a sleeve-like cylindrical structure having alongitudinally-serrated ext'erior surface around a portion of theperiphery thereof, said support means comprising on said shell-likemeans a similar longitudinally-serrated exterior surface around aportion of the periphery thereof and coaxial with the serrated exteriorsurface of said stationary means,

and a band device encircling and complementary with either of saidserrated surfaces and closely engaging one thereof and movable intoconcurrent engagement with both thereof whereby to releasably lock saidsupport means to said stationary means.

12. A device for use in effecting rotation of the adjusting shaft of ashaft-adjusted instrument whose operating range is covered by aplurality of revolutions of the adjusting shaft commencing at an initialrotational position, said shaft having an outer end and an axis ofrotation and said device indicating during rotation the extent ofrotation of the shaft from said position in terms of full revolutionsand fraction of a revolution and comprisfirst means, including supportmeans adapted for mounting upon the adjusting shaft of the instrumentfor rotation in unison therewith about the axis of rotation of theshaft, said first means including hollow shell means adapted for manualrotation about said axis and providing at least an annular window at anend thereof outwardly of the end of the instrument shaft, and said firstmeans including an outer indicator device rotatable in unison therewithabout said axis and visible through said annular window;

second means, including stationary means mechanically connected to saidfirst means and means disposed at least in part within said hollow shellmeans and supporting cam means disposed in a first generally circularpath coaxial with said axis and supporting an indicia-bearing meansvisible through said window;

third means, comprising rotatable means mechanically connected to saidfirst means and by one of said first and second means for rotation aboutsaid axis whereby said inner and outer indicator devices cogenerallybetween said shell means and said support operate with saidindicia-bearing means to provide means, said rotatable means comprisinga circular a visible indication of the extent of rotation of said set ofspaced-apart teeth disposed in a second cirfirst means from an initialposition.

cular path and an inner indicator device rotatable 5 13. A deviceaccording to claim 13, said stationary in unison therewith adjacent theface of said indiciameans comprising resilient detent means effective tobearing means; and yieldingly restrain said rotatable means againstrotation fourth means, comprising transmitter means supported incidentto absence of said transmitter from said second by said first means androtatable in unison therepath, whereby to hold said second indicatordevice stawith along at least a part of said first circular path, 10tionary relative to said indicia-bearing means between said transmittermeans comprising a resilient transstepwise movements of said secondindicator device.

mitter deflected out of said path and into driving engagement with oneof said teeth by aid cam References Cited in the file Of this patentmeans incident to rotation of said transmitter into UNITED STATESPATENTS $122525;isaarsstazttaass;212a: 15

New 7,

2,746,417 McCord et al May 22, 1956 to said rotatable means,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 151,598 October 6, 1964 Marlan E. Bourns et al.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 3, line 64 for "manner' read member column 6 lines 72 and 73,,for movement" read M movements line 73, for "betwen" read between 3column 7 line 4 for "to" read l:-.= into line 30 before "annular" insertan r line 43 for "connected to and movable in unison with" read rotatethe latter incident to rotation of same column 7 line 69, after"cirular" insert second column 8 line 75 after "and" insert supportedcolumn '10 line 5 for the claim reference numeral "13" read 12 Signedand sealed this 9th day of February 1965a (SE-AL) Atte'st:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No,3 151598 October 6, 1964 Marlan E. Bourns et al.

It is hereby certified that error appears in the above numbered patentreqiiring correction and that the said Letters Patentshould read ascorrected below.

Column 3 line 64L for "manner" read member column 6 lines 72 and 73 formovement read movements line 73, for "betwen" read between column 7 linel for "to" read e-a into line 30 before "annular" insert ane line 43 forconnected to and movable in unison with" read rotate the latter incidentto rotation of same column 7 line 69, after "cirular" insert secondcolumn 8 line 75 after "and" insert supported column lO line 5 for theclaim refer-r enoe numeral "13" read 12 Signed and sealed this 9th dayof February 1965,

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

1. FOR AN INSTRUMENT HAVING AN ADJUSTING SHAFT ROTATABLE THROUGH APLURALITY OF REVOLUTIONS IN EFFECTING ADJUSTMENT OF THE INSTRUMENTTHROUGHOUT ITS ADJUSTMENT RANGE, A TURNSINDICATING KNOB STRUCTURECOMPRISING: FIRST MEANS, INCLUDING A SUPPORT DEVICE HAVING A BORE ALONGAN AXIS AND ADAPTED FOR MOUNTING UPON THE INSTRUMENT SHAFT COAXIALLYWITH THE SHAFT, SAID DEVICE INCLUDING MEANS TO SECURE THE SUPPORT DEVICETO THE SHAFT FOR POSITIVE ROTATION IN UNISON WITH THE SHAFT ABOUT THEAXIS THEREOF; SECOND MEANS, COMPRISING ROTARY MEANS SECURED TO SAIDSUPPORT DEVICE AND PROVIDING A KNOB-LIKE EXTERIOR ADAPTED TO BE MANUALLYROTATED FOR ROTATION OF SAID SUPPORT DEVICE AND THE INSTRUMENT SHAFT,SAID ROTARY MEANS COMPRISING A TRANSPARENT WINDOW DISPOSED TRANSVERSELYOF SAID AXIS AND PROVIDING AN OUTER END FACE FOR THE ROTARY MEANS, SAIDROTARY MEANS BEARING AN OUTER INDICATOR MOVABLE IN UNISON THEREWITH ANDVISIBLE THROUGH SAID TRANSPARENT WINDOW; THIRD MEANS, INCLUDINGSTATIONARY MEANS ENCIRCLING AT LEAST A PORTION OF SAID SUPPORT MEANS ANDHAVING